Rotor and pads and bearings. Oh my!
Left rear brake disc (yes, rear disc) overheated last trip out to the point the brake fluid boiled and disc was smoking. Whether it was a sticking piston or internal kink in the final section of brak...
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Common problem, happens all the time. It can be a couple of different things. People always point at the sliding pins on the calipers but I have never had them be the culprit. More often the pads seize in their slots and very often a piston will seize due to swollen seals. I've had bad seals in the caliper piston bores only stick when the caliper is hot - when it cools off the piston freed up.
Always replace brakes in axle sets - if you do one side, do the other side too. If you replace the discs you should replace the pads as well, and vice versa. Discs are not heat treated, are cast iron not steel, and can't be annealed. Heat won't hurt them, only abnormal wear. What can be damaged by heat are pads, caliper seals and brake fluid.
Edit: bad on me for being unclear. Cast iron brake discs are indeed heat treated, but not to harden them. In the manufacturing process the discs are brought up to around 900 degrees Celsius (1650 F.) for around 4 hours. This is cherry red, and would probably cause the tire to catch fire. This anneals them, although I call it normalizing. Brake discs are also sometimes cryogenic treated, which involves taking them to a very cold temperature, which makes them a lot more wear resistant.
Brian
Always replace brakes in axle sets - if you do one side, do the other side too. If you replace the discs you should replace the pads as well, and vice versa. Discs are not heat treated, are cast iron not steel, and can't be annealed. Heat won't hurt them, only abnormal wear. What can be damaged by heat are pads, caliper seals and brake fluid.
Edit: bad on me for being unclear. Cast iron brake discs are indeed heat treated, but not to harden them. In the manufacturing process the discs are brought up to around 900 degrees Celsius (1650 F.) for around 4 hours. This is cherry red, and would probably cause the tire to catch fire. This anneals them, although I call it normalizing. Brake discs are also sometimes cryogenic treated, which involves taking them to a very cold temperature, which makes them a lot more wear resistant.
Brian
